重组酿酒酵母表达幽门螺杆菌VacA蛋白及其免疫原性分析*

目的:利用酿酒酵母表面展示技术筛选幽门螺杆菌候选疫苗,并分析其免疫原性。方法:以幽门螺杆菌的空泡型细胞毒素A(vacA)基因作为研究对象,构建重组S.cerevisiae EBY100/pYD1-VacA,通过Western blot、免疫荧光标记和流式细胞仪对S.cerevisiae EBY100/pYD1-VacA进行体外表达分析。以PBS和S.cerevisiae EBY100/pYD1为对照组,S.cerevisiae EBY100/pYD1-VacA为实验组,口服免疫SPF级BALB/c小鼠。通过ELISA分析检测口服免疫后小鼠抗VacA特异性IgG及分泌型IgA效价。结果:VacA抗原蛋白被成功地展示在S.cerevisiae EBY100表面。小鼠经口服免疫S.cerevisiae EBY100/pYD1-VacA后可诱导产生较高的VacA特异性抗体。结论:表面展示型酿酒酵母可以作为幽门螺杆菌候选疫苗的递送载体,与此同时,这也为开发其他细菌或病毒疫苗提供新思路。

Recombinant Saccharomyces cerevisiae Expressing Helicobacter pylori VacA Protein and Its Immunogenicity Analysis

Objective: Helicobacter pylori candidate vaccine was constructed based on yeast surface display technology and its immunogenicity was further analyzed. Methods: Surface displayed S.cerevisiae EBY100/pYD1-VacA was constructed that vacA gene of Helicobacter pylori as used a research subject. S.cerevisiae EBY100/pYD1-VacA was detected by Western blot analysis,immunofluorescence assay and flow cytometry assay. BALB/c mice of SPF grade were administrated orally with that PBS and S.cerevisiae EBY100/pYD1 were used as the control groups, and S.cerevisiae EBY100/pYD1-VacA was used as the experimental group. VacA-specific sera IgG and secretory IgA titers were determined by ELISA assay. Results: The VacA antigen protein was successfully displayed on the surface of S.cerevisiae EBY100. S.cerevisiae EBY100/pYD1-VacA could produce a higher VacA specific antibodies. Conclusion: Surface displayed yeast can be used as a delivery vector of Helicobacter pylori candidate vaccine. Meanwhile, it will provide new ideas for developing bacteria or virus vaccines.